Wager games come in a variety of forms, including for example a mechanical slot machine. A mechanical slot machine may include one or more reels, each of which includes a fixed pattern of symbols distributed around the circumference of the reel. When a player places a wager (e.g., by placing a coin in the machine), the player is allowed to spin the reels. Each reel then comes to rest, typically with either one of the symbols, or a space in between symbols, in alignment with a pay line. A predefined winning symbol or a predefined combination of winning symbols that are aligned with the pay line can result in the player winning the game and receiving a payout. In one example, the machine may include three reels, and the pay line may be a horizontal line disposed across a centre of each of the three reels.
In another example of a wager game, a mechanical slot machine may present symbols in a matrix arrangement, with each symbol changing during a spin of the game according to the fixed pattern of symbols on the reels. For example, the machine may have five columns and three rows of symbols, for a total of fifteen symbols. Such machines often have multiple pay lines, each being defined by a collection of positions within the matrix. For example, the machine may have three pay lines, each corresponding to one row of the matrix.
While slot machines were traditionally mechanical, modern slot machines often take the form of a video gaming machine (e.g., a dedicated gaming machine located in a casino) that includes a graphical user interface (GUI), and that may emulate a mechanical slot machine. With a video gaming machine, the GUI may display an image of one or more reels or a matrix as described above, together with animation effects to simulate a spin of the one or more reels, or a spin of the columns or rows of the matrix. A computer software program, which may reside in the video gaming machine, may randomly select one or more symbols in response to a spin, and may display the selected one or more symbols on the display.
A modern slot machine may also be played over a computer network, such as by a player using a client machine that is connected to a server machine over the computer network. In this instance, the server machine may perform the spins of the game and may send the resulting symbols to the client machine for display.
The popularity of video slot games has increased due to the incorporation of novel features, such as “wild” symbol into such video slot games. These features may assist in making winning results and provide a player with entertainment and additional opportunities to win games.